The invention relates generally to the field of welding systems, and particularly to a portable, engine driven welding system including a generator and power supply as well as a wire feeder for performing various types of welding operations.
A number of forms of welding are known and are generally used in the art. These include metal inert gas (MIG) welding, tungsten inert gas (TIG) welding, and stick welding systems. In MIG systems, electrical current is applied to a wire electrode and an arc is established between a grounded work piece and the electrode. The wire electrode is advanced through a welding torch and is generally consumed as the work piece is melted due to heat released by a sustained arc, while a shielding gas surrounds the progressing weld. A variant of MIG welding is flux core welding, in which a flux is integrated into welding wire and no shielding gas is required. In TIG welding, on the contrary, a non-consumable tungsten electrode is used to establish an arc with a work piece, the work piece material being melted and fused to form a weld, often with the addition of consumable material which is melted and added to weld under the heat of the arc. Stick welding involves establishing an arc between a stick electrode which is often surrounded by a flux material. The stick electrode is generally consumed and its metal is fused with melted metal of the work piece as the welding operation continues under the heat of an established arc. These welding techniques may be used on different types of material or for different applications, but multiple techniques are often used by a welding operator depending upon the particular needs of an application.
One difficulty in many welding applications is the need for mobility. Many complex welding systems are quite heavy and are intended only for stationary use, with work pieces being transported to the welding location. Other applications for welding, however, involve work pieces in locations that cannot be easily transported. In such applications, portable welding systems have been developed that typically include an engine driving a generator to develop electrical power required to sustain the arc used for welding. Many such systems are specifically designed for either TIG, MIG or stick welding. Where systems of this type provide any flexibility in the type of welding system that can be used, this is typically been done by the addition of add-on or optional components.
At present, there are no convenient engine-driven welding power supplies that include integral wire feeders for MIG or flux core welding. Such systems typically provide for stick welding only, and may not be configured to provide the type of power or power control suitable for MIG welding. For example, stick and TIG welding typically rely on constant current power control regimes, whereas MIG welding systems typically rely on constant voltage power control. Because no integral wire feeder is typically provided on such engine-driven systems, MIG welding operations, if possible at all, can be performed only with the use of a separate wire feeder which must be field attached to the welding power supply. Such separate units entail additional cost, must be transported separately, and must be interfaced with the welding power supply each time a MIG welding operation is to be performed.
There is a need, therefore, for improved welding systems and welding power supplies that can allow for MIG welding by means of an integral unit. There is also a need in the field for a welding power supply of this type which can be used for multiple types of welding operations by means of a single integrated unit.